So much high-minded idealism in one day, I feel exhausted. Not just David Cameron's prolix manifesto launch, which kept reminding me of Gordon Brown's, but the Lib Dems' five-point plan for curbing perverse financial incentives among risk-prone bankers. Why, I even enjoyed Ukip's manifesto launch in what must have been the smallest broom cupboard ever used for such a purpose.

Where to start? With Dave, of course. He's the one who's going to be prime minister next month unless he screws up badly. Today he didn't. Indeed, he had a little outburst of candour and eloquence about getting big government off everyone's backs that provoked real applause from his audience. Even we hacks noticed.

A very good question. The Cameroon big idea is that the state tries to do too much and does it badly. Lift the burden of tax and state intervention and a thousand flowers will bloom, says Cameron. Interviewing shadow ministers as they left Battersea power station – itself a Thatcher-era reminder of the limits of market solutions – I found that they all seemed genuinely fired up by it, even Sir George Young, who is old enough to know better.

It's a lovely idea. George Bush Sr got elected on a version of it – do you remember "one thousand points of light"? – in 1988 and unelected on it by Bill Clinton in 1992. The tension that exists between actions that are appropriate to collective solutions and those better solved in the private sphere is enduring. There's no easy answer.

But a nation of volunteers? Not sure about that. The collapse of voluntary action has been a marked feature of the past 30 years. Many of us have become two-income working families, earning money to survive or to afford the new widescreen TV and the second foreign holiday. It's hard to get people to serve as school governors, let alone to start whole new schools along Swedish lines.

Never mind. It was a decent and wholesome event, though weirdly staged inside a steel and canvas tent inside the shell of the famous power station. They shot movies here, good and bad, Dave told us, including an Ashes to Ashes episode and a Doctor Who.

Yet the party's most bankable performer, Ken Clarke, was parked well out of the shot and denied a platform speech – unlike George Osborne, Michael Gove, Andrew Lansley, Theresa (who she?) May, Caroline (ditto) Spelman and Lady Warsi. At least they all have jobs. Most of the women on the platform were there as decoration, symbols of gender and ethnic diversity.

Personally, I think Warsi – a northern, Muslim woman and lawyer – has potential, and I retain an irrational fondness for Osborne (whom I barely know). But the rest are second order players. Whoops, I forgot William Hague, whom I once hoped that advancing years would improve. Instead I have come to see him as slightly sinister. It's that eastern European thing of his, I think.

None of it cut much ice at the Ukip launch, where Nigel Farage, the party's ex-leader, MEP and wannabe MP for Speaker Bercow's Buckingham seat, held court with his successor, Lord Malcolm Pearson of Rannoch, and Lord David Campbell-Bannerman, the descendant of a Liberal prime minister. They all complained that the election so far has been boring and ducked the real issues.

What is a week's debate on £6bn worth of national insurance charges when we pay £16bn a year to the EU and borrowed £170bn last year, they asked. "We are no longer a single-issue party," insisted DCB before rattling off a long list of implausible policies such as leaving the EU; electing county health boards; putting matron in charge on the ward; including non-academic skills in the 11-plus; cutting out red tape, especially EU red tape; spending 40% more on the army ... And so on.

Lots of gorgeous stuff in the small print, but idealistic and well-meant in its way. They are all oozing sincerity in this campaign. It's the ungrateful voters who drip with cynicism.

But Ukip's package struck me as the sort of manifesto lots of Tories would write after drinking a pint or so of white wine and a couple of pink gins on a Saturday night, but bin when they woke up with a headache and read it on Sunday morning. That's probably what most floating Tory voters will probably do on 6 May too, the temptation to vote in a winner after 13 years is too great to resist.

All spent on staff, not a penny on me, he said. And the wife's salary? She worked for free until 2007, he replied, unblinking. And that's the new politics talking ...

What is undeniably new is Ukip's policy of urging voters not to vote for their candidate in places where six Tory MPs and one Labour are so Eurosceptic that they win Ukip's approval. Posters are going up saying "Ukip says vote Tory here, but vote Ukip if you really don't want to." Fun, eh?

Try as it may, Ukip keeps coming back to its core subject: Europe. Pearson said this was the last chance to resist the European superstate; it would soon all be over for Britain as an independent country. Yet the three most contentious policies of the last decade – Iraq, the unfettered banking system and the unbalanced UK budget – were all carried out in express defiance of EU sentiment and policy, I mused aloud. We had an enjoyable spat, mediated by Andrew Neil's heckles.

And so to the Lib Dems' 7.30 am session, the bribe for attendance being bacon sarnies and decent coffee. Clegg and Vince Cable unveiled a sensible five-point plan for discouraging testosterone-soaked bankers from ruining us all to win huge bonuses. It sounded perfectly sensible to me. They want bonuses paid mostly in deferred shares; they even want banks that aren't in profit to be forbidden from paying bonuses at all. Shocking!

What was interesting was that Clegg handled the economic stuff with almost as much fluency and confidence as the saintly Cable. I hadn't spotted that. 22 days to go.